This description relates to assigning portions of a code space to portable base stations.
Cellular communication systems include antenna towers erected in fixed locations to provide wireless coverage to devices such as cellular phones, personal digital assistants (PDAs) and computer systems (each of which is referred to as an Access Terminal or AT). In some situations an AT may be located within the coverage area of multiple towers. To distinguish one tower from another, each tower transmits a unique identification signal that includes information assigned to the tower. This information may be a sequence of pseudorandom numbers (PN) that are transmitted in a repetitive manner. To uniquely identify each tower, transmission of the PN sequence is initiated from different elements in the sequence or different sequences may be transmitted. Using one PN sequence, the starting elements may be identified by a number that represents the offset from the first element in the sequence to the starting element (assigned to the tower). Prior to becoming operational, different offsets may be assigned to the towers in a procedure known as radio frequency (RF) planning that seeks to protect against interfering identification signals being transmitted from two or more closely located towers.